Spotty results in our Sw-7 tomato spotted wilt virus research. J.W. Scott, S.F. Hutton, S.M. Olson, and M.R. Stevens

Transcription

1 Spotty results in our Sw-7 tomato spotted wilt virus research J.W. Scott, S.F. Hutton, S.M. Olson, and M.R. Stevens

2 Florida Principle Tomato Producing Areas Gadsden Oxford Palmetto- Ruskin Wimauma Ft Pierce Pompano Immokalee- Naples Dade

3 Background Pedigree L. esculentum x L. chilense (LA 1938) Interspecific hybrid (F 1 ) F 1 BC 1 Fla 7482B = x F 1 F 1 BC 1 S 5 = IE925F-2 from ToMoV resistance program F 2 = CK12 Fla 7482B x F 3 F 4 CK12 (red) F 1 F 2 = sent to Florida

4 God knows I love the South

5 Fla. 8516, 8516B and 8516C Spring 2002: (Fla x CK12) F 2 s selected (1 of 9 selections = F 3 seed) [No TSWV]. Spring 2004: Seven selections were made under 50% TSWV infection (F 4 seed). Spring 2005: 3 of 7 F 4 selections were homozygous resistant = Fla. 8516, 8516B, and 8516C. Fall 2005: Fla crossed to 21 parent lines. Spring 2006: 15 F 1 s advanced to F 2. Fall 2006: 102 F 2 plants selected (F 3 seed) [No TSWV infection]. Spring 2007: F 3 s and controls field tested for TSWV incidence.

6 Tomato spotted wilt disease incidence for seven lines derived from L. chilense LA1938 and control hybrids grown in South Georgia, Spring 2005 plus Chisquare test for goodness of fit to a single dominant gene model. Genotype Total No. Plants Healthy No. Diseased No. (%) Conclusion y Chisquare (3:1) 1.28 P (29) Seg (8516B) (0.8) R 9-3 (8516) (0.8) R (69) S (28) Seg (8516C) (0.8) R (34) Seg Crista (Sw-5) (1.5) R - control Mt. Spring (57) S - control z There was an average of 63% infection for the 2 susceptible genotypes 9-4 and Mt. Spring. y R = resistant, Seg = segregating, S = susceptible.

7 Fla. 8516

8 Segregation of F 3 tomato and control lines for incidence of tomato spotted wilt virus and chi-square tests for control by a single dominant gene at Quincy, Florida in spring Number of plants Line(s) z Total Resistant Susceptible χ 2 3:1 ρ Fla Fla Homozygous resistant 9 lines 30, 29 all lines lines = 26 z Fla is the resistant control, Fla is the susceptible control. F 3 lines categorized as homozygous resistant, heterozygous resistant or homozygous susceptible based on chi-square tests for 3:1 ratios that were significant due to an excess of resistant plants, had acceptable fits, or were significant due to an excess of susceptible plants, respectively.

9 Number of plants Line(s) z Total Resistant Susceptible χ 2 3:1 ρ 5 lines lines lines lines lines lines = 39

10 Number of plants Line(s) z Total Resistant Susceptible χ 2 3:1 ρ 3 lines lines lines < < < lines < lines < lines lines lines lines lines = 37 χ 2

11 Goodness of Fit Test F 3 line segregation- 26R:39Seg:37S Χ 2 1:2:1=8.019, p=

12 Tomato spotted wilt virus disease incidence for selected hybrids, Hybrid TSWV (%) TSWV Gene(s) Shanty 0. 0 d z Sw-5 Top Gun 5. 2 d Sw-5 Fla d Sw-5 and Sw-7 Fla c Sw-7 Fla c Sw-7 Tygress 42.1 b (Susc) Florida a (Susc) z Mean separation in columns by DMRT at P <0.05.

13

14 Sw-7 Recombinant Population Chr 12 Sw-7 introgression from S. chilense LA1938 identified on chr. 12 (Dockter, et al HortScience 44:1123) Fall 2009 MAS [7777 x (7777 x 8516)] F 2 [8111 x (8111 x 8516)] F 2 [8249 x (8249 x 8516)] F 2 [7776 x (7776 x 8516)] F 2 [8021 x (8021 x 8516)] F 2 [8022 x (8022 x 8516)] F 2 Recombinants (30) (17) (13) (4) (1) (1) ~45 cm T1263 SL 10953i CT100 TG360 CT99 T1736 ~2.97 Mb Each recombinant selfed and RILs selected RILs evaluated in Quincy in Spring 2011 RCBD with 3 reps and 10-plant plots ~58 cm SSR20

15 Spring 2011 Sw-7 RIL Population Marker Recombination Events SL2.40ch12 R S SL10953i CT (106 Kb) 3.79 Mb (786 Kb) TG360 CT99 T (27 Kb) (44 Kb) (2055 Kb) SSR

16 Spring 2011 Sw-7 RIL Population Marker SL2.40ch12 R S SL10953i 3.79 Mb CT100 TG360 CT99 T SSR Number of RILs (0) (1) (4) (6) (0) (0) (0) (8) (2) Total Plants (0) (6) (11) (15) (0) (0) (0) (14) (3) % RILs w/ Incidence % Infected Plants

17 Spring 2011 Sw-7 RIL Population Marker SL2.40ch12 R S CT Mb P P P P TG # RILs Plants

18 Status of Sw-7 Research Clarify the gene action of Sw-7 Determine if germplasm with Sw-7 gets fruit blotch Verify fine mapping results All the above require adequate disease pressure in the field Note: Sw-7 can not be screened by mechanical seedling inoculation

19 Namaste. Zen Mindset II To maintain a Zen Mindset it is best to have time to adjust to bad policies before they occur. When administrators get together and one of them comes up with a bad idea, others are quick to adopt it. An example is using Journal Impact Scores to evaluate refereed publications. So when you hear of something bad elsewhere begin to accept it because it is coming home soon.